Why the New Coronavirus Unnerves Public Health: Remembering SARS

On Feb. 21, 2003, a 65-year-old physician who lived in the Chinese province that abuts Hong Kong crossed into the territory surrounding the city and checked into a hotel in Kowloon. He was given a room on the ninth floor. Sometime during his stay — no one has ever fully traced his path — he encountered roughly a dozen other people; most of them were hotel guests whose rooms were on the same floor, but some were staying on other floors, and some were visitors to events there. The physician had been sick for a week with symptoms that had started like the flu, but were turning into pneumonia, and the next day, he checked out of the hotel and went to a Hong Kong hospital. Before the end of the day, he died.

In the next few days, the people who had crossed paths with the physician left the hotel. Most of them were visitors to the special administrative region: Hong Kong is not only a port and transit hub, but a business and shopping destination for much of the Pacific Rim. They went to Vietnam, Singapore, Canada, and Ireland. As they traveled, some of them started to feel as though they had picked up the flu.

The CDC’s 2003 diagram of the first SARS cases outside China.

Within a month, health authorities in 14 countries had identified more than 1,300 cases of respiratory illness that all traced back to those brief encounters somewhere in the hotel. Within five months, the illness — dubbed SARS, for severe acute respiratory syndrome — had caused 8,098 illnesses, and 774 deaths in 26 countries around the world.

SARS (which had been brewing in China for months but never previously escaped) was caused by a novel coronavirus, for which there was no uncomplicated treatment and no vaccine, and despite being seeded in a very small group of people, it spread rapidly around the world. That goes a long way to explain why health authorities are so unnerved now by the identification of another novel coronavirus, which has been identified in a part of the world where millions of people are about to converge, mingle and leave.

The World Health Organization has issued an alert and written a preliminary case definition, which because it is early in this episode is so loose — involving fever, cough and either travel to Qatar or Saudi Arabia, or contact with someone who did — that it is likely to turn up many unrelated cases that could temporarily inflate the numbers.

The virus is so new that it has not been named officially, but as of last night it had been partially sequenced and aligned with other coronoviruses including the SARS virus. The dendrogram, and information about lab options for molecular diagnostics, were posted last night by the U.K.’s Health Protection Agency. (Soon afterward, virologist and commentator Vincent Racaniello cautioned that Koch’s postulates haven’t yet been fulfilled, underlining that the virus has been isolated from people with respiratory symptoms, but has not yet been proven to cause those symptoms.)

And the WHO’s spokesman on the emerging virus, Gregory Hartl, has repeatedly reminded media covering the story that (as he said in a briefing taped Tuesday) “this is not SARS, it will not become SARS, it is not SARS-like” — a point that was not necessarily meant to be a reassurance, since he added, “It is distinct from SARS at least in the fact that we’ve seen so far, it causes very rapid renal failure.”

The concern underlying these developments is that exposure to the new virus seems to have occurred only or primarily in Saudi Arabia, which houses Mecca, the physical heart of Islam — and which, next month, will be the center of the worldwide annual pilgrimage known as the Hajj. The Hajj brings more than 2 million people to the country, in extraordinarily crowded conditions, and when those pilgrims leave, they disperse all over the world.

The spread of disease during the Hajj has always been a concern (discussed, for instance, in this UK document from 2005, when avian flu H5N1 was a cross-border threat), and the Saudi authorities have always taken it seriously, including requiring that pilgrims be vaccinated in order to be granted a visa. According to news reports today, they are ramping up scrutiny of visitors, who have already begun arriving: The first official day of the pilgrimage season this year is tomorrow, Sept. 27, though the central observances in Mecca do not begin until Oct. 24.

Given the periodically flaring tensions between the Islamic world and the West — exemplified most recently by the attack on the U.S. embassy in Libya — preventing the Hajj from being identified with the spread of a disease is a priority not just for health authorities, but for governments. But a month is a long lead time in modern public health, even given how fast diseases such as SARS can spread. Meanwhile, here are some key sources to watch for news:

The blogs of Mike Coston and Crawford Kilian, who do a phenomenal and completely unrecompensed job of keeping track of international developments in public health.

It is also a good idea to watch for any stories by Helen Branswell of the Canadian Press, one of very few reporters who covered SARS almost a decade ago and is still on the beat (with this story, for instance). I also covered SARS, and I’ll do my best to update here.

Almost immediate update: As an example of how fast things are moving, just as I hit the button on this, Agence France Presse posted a report that the five Danish cases have been diagnosed with influenza B.